synchronization

What is the difference between Clojure STM (dosync) approach and Java synchronize Block? I'm reading the code below from "The sleeping barber" problem. ( http://www.bestinclass.dk/index.clj/2009/09/scala-vs-clojure-round-2-concurrency.html ) (defn the-shop [a] (print "[k] entering shop" a) (dosync (if (< (count @queue) seats) (alter queue conj a) (print "[s] turning away customer" a)))) To avoid race conditions, dosync is used, so i ask myself "What is the difference (STM) from Java synchronize block" ? Will it block this critical code ? Thanks in advance ! Dantas dosync and synchronized give

The lock statement ensures that one thread does not enter a critical section of code while another thread is in the critical section. However, it won't work if the workload is spread across a farm of servers (e.g. a few IIS servers + a load balancer). Does .NET support such a scenario? Is there any class that can be used to control the execution of a critical code section by threads running on multiple machines? If not, is there any standard method of handling such problems? This question was inspired by a discussion that started here but is not limited to SharePoint or ASP.NET. Kit If you

I have a situation where a notify() 'can' be called before a wait(). I am trying to make a simulator to schedule its next event when I 'notify' him by sending him messages. So I have devised a wait->notify->scedule chain void Broker::pause() { boost::unique_lock<boost::mutex> lock(m_pause_mutex); { std::cout << "pausing the simulation" << std::endl; m_cond_cnn.wait(lock); std::cout << "Simulation UNpaused" << std::endl; // the following line causes the current function to be called at // a later time, and a notify() can happen before the current function // is called again Simulator::Schedule

Lucene documentation states that single instances of IndexSearcher and IndexWriter should be used for each index in the whole application, and across all threads. Also, writes to an index will not be visible until the index is re-opened. So, I'm trying to follow these guides, in a multi-threaded setup. (a few threads writing, multiple user threads searching). I don't want to re-open the index on every change, rather, I want to keep searcher instance not older than a certain amount of time (say, like 20 seconds). A central component is responsible to open index readers and writers, and keep the